public class Main {
    public static void main(String[] args) {
        Mediator mediator = new ConcreteMediator();

        Colleague colleagueA = new ConcreteColleagueA(mediator);
        Colleague colleagueB = new ConcreteColleagueB(mediator);

        mediator.addColleague(colleagueA);
        mediator.addColleague(colleagueB);

        colleagueA.send("早上好，张三同事！");
        colleagueB.send("早上好，李四同事！");
    }
}